On 64-bit platforms such as x86_64, glibc is usally built with 32-bit
compatibilty for various structures. One of them is utmp.

What this means is that gettimeofday(&ut.ut_tv, NULL) on x86_64 will
end up overwriting the first parts of ut_addr_v6, leading to garbage
in the utmp file.


--- util-linux-2.13-pre6/login-utils/login.c.kzak	2006-08-10 11:38:33.000000000 +0200
+++ util-linux-2.13-pre6/login-utils/login.c	2006-08-10 11:38:49.000000000 +0200
@@ -257,6 +257,7 @@
 static void
 logbtmp(const char *line, const char *username, const char *hostname) {
 	struct utmp ut;
+	struct timeval tv;
 
 	memset(&ut, 0, sizeof(ut));
 
@@ -267,7 +268,9 @@
 	xstrncpy(ut.ut_line, line, sizeof(ut.ut_line));
 
 #if defined(_HAVE_UT_TV)	    /* in <utmpbits.h> included by <utmp.h> */
-	gettimeofday(&ut.ut_tv, NULL);
+	gettimeofday(&tv, NULL);
+	ut.ut_tv.tv_sec = tv.tv_sec;
+	ut.ut_tv.tv_usec = tv.tv_usec;
 #else
 	{
 		time_t t;
@@ -872,6 +875,7 @@
     {
 	struct utmp ut;
 	struct utmp *utp;
+	struct timeval tv;
 	
 	utmpname(_PATH_UTMP);
 	setutent();
@@ -911,7 +915,9 @@
 	strncpy(ut.ut_user, username, sizeof(ut.ut_user));
 	xstrncpy(ut.ut_line, tty_name, sizeof(ut.ut_line));
 #ifdef _HAVE_UT_TV		/* in <utmpbits.h> included by <utmp.h> */
-	gettimeofday(&ut.ut_tv, NULL);
+	gettimeofday(&tv, NULL);
+	ut.ut_tv.tv_sec = tv.tv_sec;
+	ut.ut_tv.tv_usec = tv.tv_usec;
 #else
 	{
 	    time_t t;